US4864561A - Technique for improved subjective performance in a communication system using attenuated noise-fill - Google Patents

Technique for improved subjective performance in a communication system using attenuated noise-fill Download PDF

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Publication number
US4864561A
US4864561A US07/209,458 US20945888A US4864561A US 4864561 A US4864561 A US 4864561A US 20945888 A US20945888 A US 20945888A US 4864561 A US4864561 A US 4864561A
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United States
Prior art keywords
noise
end user
signal transmission
signal
destined
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Expired - Lifetime
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US07/209,458
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English (en)
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Robert C. Ashenfelter
Marco J. Bonomi
Duane O. Bowker
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Nokia Bell Labs
AT&T Corp
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American Telephone and Telegraph Co Inc
AT&T Bell Laboratories Inc
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Assigned to AMERICAN TELEPHONE AND TELEGRAPH COMPANY, A CORP. OF NEW YORK, BELL TELEPHONE LABORATORIES, INCORPORATED, A CORP. OF NEW YORK reassignment AMERICAN TELEPHONE AND TELEGRAPH COMPANY, A CORP. OF NEW YORK ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: BONOMI, MARCO, J.,, ASHENFELTER, ROBERT C., BOWKER, DUANE, O.,
Priority to US07/209,458 priority Critical patent/US4864561A/en
Priority to CA000598961A priority patent/CA1332453C/fr
Priority to JP1139008A priority patent/JPH0239744A/ja
Priority to AU35969/89A priority patent/AU596333B2/en
Priority to EP19890305849 priority patent/EP0348078A3/fr
Priority to CN89104045A priority patent/CN1038730A/zh
Priority to KR1019890008361A priority patent/KR920007478B1/ko
Publication of US4864561A publication Critical patent/US4864561A/en
Application granted granted Critical
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B1/00—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
    • H04B1/06—Receivers
    • H04B1/10—Means associated with receiver for limiting or suppressing noise or interference
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04J—MULTIPLEX COMMUNICATION
    • H04J3/00—Time-division multiplex systems
    • H04J3/17—Time-division multiplex systems in which the transmission channel allotted to a first user may be taken away and re-allotted to a second user if the first user becomes inactive, e.g. TASI

Definitions

  • the present invention relates to a technique for providing improved subjective performance in a communication system or network. More particularly, during moments when no speech or other information signal is being transmitted to an end user during a call, a noise-fill level is provided to a connected end user which is at a predetermined level below that normally found on a channel when there is both an information signal and a noise signal being received.
  • An exemplary communication system that uses a noise-matching technique is described, for example, in (1) the article "TASI-E Communication System" by R. L. Easton et al. in IEEE Transactions On Communications, Vol. COM-30, No. 4, April 1982, at pages 803-807, and in particular at pages 804 and 805, and (2) in U.S. Pat. No. 4,408,324 issued to D. H. A. Black et al. on Oct. 4, 1983.
  • a channel-checking arrangement is used to periodically measure, inter alia, the noise on the channels of the system, the measured channel noise then being used along with the measured background noise on the incoming trunk in a noise-matching operation during silent periods on the channel.
  • such communication system when a trunk is not connected to a channel, such communication system inserts noise at the transmitting or receiving end of that channel to make the total noise at the channel output equal to the same value as when the trunk is connected to the channel and a signal is being transmitted over the channel, thereby avoiding various effects such as noise-pumping.
  • the problem remaining in the prior art is to provide a technique which can further improve, if possible, the subjective performance of a communication system, which includes speech interpolation and may or may not include noise-matching.
  • the foregoing problem in the prior art has been solved in accordance with the present invention which relates to a technique in a communication system such as, for example, a Wideband Packet Technology (WPT) Access Interface (AI) with speech interpolation, wherein a noise measurement at the transmitter end, or the reproduced noise-fill at the receiver end, is attenuated or reduced by a predetermined amount from the average monitored level of noise normally received over a channel when communication is taking place before being provided to an end user during non-information transmission periods.
  • WPT Wideband Packet Technology
  • AI Voice Interpolation
  • FIG. 1 is a block diagram of pertinent parts of an exemplary communication system employing the reduced noise-fill technique of the present invention
  • FIG. 2 depicts an exemplary arrangement for a combination of a speech detector, noise measuring means and attenuator in the transmitter of FIG. 1;
  • FIG. 3 is a graph representing exemplary result of providing improved subjective performance of speech transmission by reducing the amount of noise fill provided during gaps in the speech transmission below the point (0 dB) where the matched noise level is exactly equal to the input noise level.
  • FIG. 1 shows only pertinent parts of a transmitter 10 and a receiver 20 within a communication system for practicing the present noisematching technique, where information signal detection and noise measurements are performed at transmitter 10 and used at both the transmitter 10 and the associated receiver 20.
  • the information signal used as an input to transmitter 10 is a speech signal, but it should be understood that the information signal could comprise any other information signal, such as a music signal, that a person associated with a remote receiver might be listening to.
  • any form of information signal transmission can be used for practicing the present invention of noise matching, as, for example, analog, digital or packet transmission with a wideband or narrow band spectrum, since the form of transmission is arbitrary.
  • the input speech signal from a first end user at input 11 is directed to each of (a) a first input terminal 13 of a switching means 12, (b) a speech detector 16, and (c) a noise measuring arrangement 17.
  • Another input signal, such as data signals, that might be sent over the same communication channel 18 between transmitter 10 and receiver 20 is provided as an input to a second input terminal 14 of switching means 12.
  • Speech detector 16 monitors input 11 to determine whether a speech signal is active (present) or inactive (not present) and provides an output control signal which is representative of the speech activity and is received by both switching means 12 in transmitter 10 and remote receiver 20 via communication channel 18.
  • the control signal from speech detector 16 causes switching means 12 in transmitter 10 to (a) connect input terminal 13 to output terminal 15 when a speech signal is being detected at input 11 in order to transmit the detected speech signal to receiver 20 over communication channel 18, and (b) to connect input terminal 14 to output terminal 15 when a speech signal at input 11 is not detected in order to transmit the other input signal, when present, arriving at second input terminal 14 of switching means 12 to receiver 20 over communication channel 18.
  • the other input signal on input 14 of switching means 12 can be, for example, a packet signal which has its packets stored in a memory (not shown) for transmission by a gating means (not shown) which is responsive to the same speech detector output control signal that causes switching means 12 to connect its input 14 with its output 15. In this manner other signals can be transmitted on communication channel 18 when it is not being used for the speech signal transmission and thereby provide a Speech Interpolation technique.
  • Noise measuring arrangement 17 is used to determine the level of the background noise in the speech signal at input 11 and to generate a background noise level control signal for transmission either directly to receiver 20 over communication channel 18 or indirectly to receiver 20 via optional attenuator arrangement 19.
  • attenuator arrangement 19 when attenuator arrangement 19 is present in transmitter 10, it functions to reduce the value of the determined background noise level by a predetermined amount before being transmitted to receiver 20 over channel 18.
  • attenuator arrangement 19 is an optional element and (a) is, therefore, shown by dashed lines, and (b) when present in transmitter 10 can form a part of noise measuring arrangement 17.
  • attenuator arrangement 19 can be disposed in receiver 20 as an optional attenuator arrangement 22 as will be described hereinafter.
  • concurrent information, active/inactive, and noise value signals transmitted on communication channel 18 are transmitted as separate portions of an overall communication signal and, therefore, can be concurrently transmitted in any suitable manner such as, for example, on separate leads or in a composite signal in, for example, the header and information portions of a packet or in different frequency subbands of the composite signal.
  • speech detector 16 and noise measuring arrangement 17 may actually be formed as part of one circuit as will be shown hereinafter in FIG. 2, but is described here as separate elements for ease of description.
  • the active/inactive control signal portion is received by each of a first and a second switching means 23 and 27 in order to control the path through these switching means; (b) the information signal portion is received at an input terminal 28 of second switching means 27; and (c) the noise value control signal portion is received by a noise generator 21.
  • Noise generator 21 is responsive to the background noise level control signal transmitted by noise measuring arrangement 17 in transmitter 10 for generating a level of noise which corresponds to the level of background noise indicated by the received background noise level control signal.
  • the background noise signal produced by noise generator 21 is provided to the input terminal 24 of first switching means 23 either (a) directly when the noise value signal from noise measuring arrangement 17 has been previously attenuated by the predetermined amount in attenuator 19, or (b) indirectly via attenuator 22 when the noise value signal from noise measuring arrangement 17 has not been previously attenuated before being transmitted.
  • optional attenuator 22 can be a separate circuit, disposed before or after noise generator 21, or form a part of noise generator 21.
  • speech detector 16 at transmitter 10 detects the presence of a speech signal, including background noise, at input 11, it generates a control signal having first value which is transmitted to receiver 20 while simultaneously causing switching means 12 to connect input terminal 13 to output terminal 15 and thereby transmit the speech signal, and included background noise, to receiver 20.
  • the received second value control signal from speech detector 16 causes first switching means 23 to close the path between input terminal 24 and output terminal 25 to direct the attenuated noise fill signal obtained from noise generator 21 and optional attenuator 22 (when present) onto first output path 31 from receiver 20, while simultaneously causing second switching means 27 to close the path between input terminal 28 and output terminal 29 to direct the received other information signals onto a second output path 32 from receiver 20.
  • first and second switching means 23 and 27 at receiver 20 can have any suitable arrangement to realize comparable interconnections.
  • FIG. 2 In an exemplary wideband packet technology transmitter 10, which is also known as an access interface (AI), with digital speech interpolation, an exemplary arrangement for providing noise matching in transmitter 10 according to the present invention is shown in FIG. 2.
  • speech detector 16 noise measuring arrangement 17 and optional attenuator 19 of FIG. 1 can all be formed as part of speech detector 16.
  • Noise matching involves two functions, noise level estimation and noise generation. Noise level estimation is performed as part of the speech detection function in speech detector 16 by the following exemplary digital circuits.
  • the speech signal at input 11 is high-pass filtered in HP filter 40 to reduce hum and remove any DC component.
  • the resultant signal is full-wave rectified in rectifier 41 and then low-pass filtered in LP filter 42.
  • the resulting envelope signal is monitored in peak monitor circuit 43 for the peaks and minima levels. These peak and minima levels are taken to be measures of the speech level and the background noise level, respectively, and are used by speech detector 16 in setting its speech threshold.
  • attenuator 19 when the noise value to be transmitted to receiver 20 is to be attenuated before transmission to receiver 20, optional attenuator 19 would be used with a noise level translator 44 to provide a digital noise value which is at the predetermined reduced or attenuated value. It is to be understood that attenuator 19 can be either before or after or a part of noise level translator 44.
  • the noise level measure from speech detector 16 can be made available as, for example, an 8-bit quantity for transmission to noise level translator 44 and/or attenuator 19.
  • the range of noise levels this represents could be divided into 16 exemplary parts and translated to a 4-bit noise level value by noise level translator 44.
  • This 4-bit noise level value would be transmitted in, for example, the header of each speech packet during the period when the end user associated with input 11 is active and providing a speech signal.
  • the noise level value transmitted in the last packet, and received at receiver 20 is used to generate an appropriate random noise signal by noise generator 21, which noise signal is inserted in the speech gap at output 31 by switching means 23.
  • noise generator 21 for each of the 16 noise levels, noise generator 21 can produce a random or pseudorandom sequence of Pulse Code Multiplex (PCM) samples with the desired noise powers.
  • PCM Pulse Code Multiplex
  • the noise fill signal to be provided during gaps in the output speech signal at output 31 of receiver 20 to provide improved subjective performance of speech signals was found to occur when the noise signal reduced below the 0 dB noise match value. More particularly, in an illustrative example shown in FIG. 3, the subjective performance of speech transmission is found to be improved, in accordance with the concept of the present invention, as the noise fill signal is reduced below the 0 dB noise match value. From the graph of FIG. 3, it can be seen that the subjective performance was found to increasingly improve as the background noise fill is decreased from the 0 dB noise match value until it reaches a maximum between the -3 and -6 dB noise match value depending on the actual noise level at input 11.
  • the subjective performance was found to decrease at noise match values below -3 dB. Therefore, it is shown that the end users find the subjective performance of speech transmission better when the noise match level is reduced below the 0 dB, level with the best subjective performance occurring between the -3 and -6 dB noise match levels.

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  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Noise Elimination (AREA)
  • Time-Division Multiplex Systems (AREA)
  • Telephone Set Structure (AREA)
US07/209,458 1988-06-20 1988-06-20 Technique for improved subjective performance in a communication system using attenuated noise-fill Expired - Lifetime US4864561A (en)

Priority Applications (7)

Application Number Priority Date Filing Date Title
US07/209,458 US4864561A (en) 1988-06-20 1988-06-20 Technique for improved subjective performance in a communication system using attenuated noise-fill
CA000598961A CA1332453C (fr) 1988-06-20 1989-05-08 Methode ayant recours au remplissage par un bruit attenue pour ameliorer subjectivement la performance d'un systeme de communication
JP1139008A JPH0239744A (ja) 1988-06-20 1989-05-31 雑音整合方法及び雑音整合を行なう受信器
AU35969/89A AU596333B2 (en) 1988-06-20 1989-06-01 Technique for improved subjective performance in a communication system using attenuated noise-fill
EP19890305849 EP0348078A3 (fr) 1988-06-20 1989-06-09 Technique de modification du fonctionnement subjectif dans un système de communication utilisant un remplissage par du bruit atténué
CN89104045A CN1038730A (zh) 1988-06-20 1989-06-16 利用衰减的充填噪声改善通信系统中主观评定性能的技术
KR1019890008361A KR920007478B1 (ko) 1988-06-20 1989-06-17 노이즈 정합 방법 및 수신기

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US07/209,458 US4864561A (en) 1988-06-20 1988-06-20 Technique for improved subjective performance in a communication system using attenuated noise-fill

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EP (1) EP0348078A3 (fr)
JP (1) JPH0239744A (fr)
KR (1) KR920007478B1 (fr)
CN (1) CN1038730A (fr)
AU (1) AU596333B2 (fr)
CA (1) CA1332453C (fr)

Cited By (23)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1991013498A1 (fr) * 1990-02-28 1991-09-05 Motorola, Inc. Systeme de placement de plages vides et de remplissage base sur la selection categorielle
US5065395A (en) * 1990-04-09 1991-11-12 Dsc Communications Corporation Rudimentary digital speech interpolation apparatus and method
US5414796A (en) * 1991-06-11 1995-05-09 Qualcomm Incorporated Variable rate vocoder
WO1996013916A1 (fr) * 1994-10-28 1996-05-09 International Mobile Satellite Organization Procede de communication et dispositif de transmission d'un second signal en l'absence d'un premier
US5559832A (en) * 1993-06-28 1996-09-24 Motorola, Inc. Method and apparatus for maintaining convergence within an ADPCM communication system during discontinuous transmission
US5615214A (en) * 1995-10-30 1997-03-25 Motorola, Inc. System and method of compensating propagation time variations and substituting for lost packets in a packetized voice communication system
US5625687A (en) * 1995-08-31 1997-04-29 Lucent Technologies Inc. Arrangement for enhancing the processing of speech signals in digital speech interpolation equipment
US5657422A (en) * 1994-01-28 1997-08-12 Lucent Technologies Inc. Voice activity detection driven noise remediator
US5680420A (en) * 1993-02-26 1997-10-21 Nokia Technology Gmbh Device for producing a noise detector signal
US5742734A (en) * 1994-08-10 1998-04-21 Qualcomm Incorporated Encoding rate selection in a variable rate vocoder
US5751901A (en) * 1996-07-31 1998-05-12 Qualcomm Incorporated Method for searching an excitation codebook in a code excited linear prediction (CELP) coder
US5881373A (en) * 1996-08-28 1999-03-09 Telefonaktiebolaget Lm Ericsson Muting a microphone in radiocommunication systems
US5911128A (en) * 1994-08-05 1999-06-08 Dejaco; Andrew P. Method and apparatus for performing speech frame encoding mode selection in a variable rate encoding system
US6295302B1 (en) 1998-04-24 2001-09-25 Telefonaktiebolaget L M Ericsson (Publ) Alternating speech and data transmission in digital communications systems
US6438131B1 (en) * 1998-07-28 2002-08-20 Lucent Technologies Inc. Low-overhead service specific convergence layer for voice and telephony over packet-based systems
DE19630113C2 (de) * 1995-08-02 2003-09-18 Motorola Inc Verfahren zum Senden von Daten während Sprachpausen in einem synchronen Kommunikationssystem
US6691084B2 (en) 1998-12-21 2004-02-10 Qualcomm Incorporated Multiple mode variable rate speech coding
US6873604B1 (en) * 2000-07-31 2005-03-29 Cisco Technology, Inc. Method and apparatus for transitioning comfort noise in an IP-based telephony system
US7065498B1 (en) * 1999-04-09 2006-06-20 Texas Instruments Incorporated Supply of digital audio and video products
US20060227963A1 (en) * 2005-04-07 2006-10-12 Ascalade Communications Inc. Wireless multi-unit conference phone
US20070248813A1 (en) * 2006-04-25 2007-10-25 Xerox Corporation Imaging member having styrene
US20080049647A1 (en) * 1999-12-09 2008-02-28 Broadcom Corporation Voice-activity detection based on far-end and near-end statistics
RU2651803C1 (ru) * 2016-12-22 2018-04-24 Акционерное общество "Научно-производственное предприятие "Полет" Подавитель шума

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GB9006088D0 (en) * 1990-03-17 1990-05-16 Digital Equipment Int Interference suppression
WO1999013664A1 (fr) * 1997-09-12 1999-03-18 Telefonaktiebolaget Lm Ericsson (Publ) Procede et dispositif de separation de signalisation et de son vocal dans un systeme telephonique mobile analogique

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Cited By (31)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1991013498A1 (fr) * 1990-02-28 1991-09-05 Motorola, Inc. Systeme de placement de plages vides et de remplissage base sur la selection categorielle
US5095540A (en) * 1990-02-28 1992-03-10 Motorola, Inc. Hole placement and fill system based on category selection
US5065395A (en) * 1990-04-09 1991-11-12 Dsc Communications Corporation Rudimentary digital speech interpolation apparatus and method
US5657420A (en) * 1991-06-11 1997-08-12 Qualcomm Incorporated Variable rate vocoder
US5414796A (en) * 1991-06-11 1995-05-09 Qualcomm Incorporated Variable rate vocoder
US5680420A (en) * 1993-02-26 1997-10-21 Nokia Technology Gmbh Device for producing a noise detector signal
US5559832A (en) * 1993-06-28 1996-09-24 Motorola, Inc. Method and apparatus for maintaining convergence within an ADPCM communication system during discontinuous transmission
US5657422A (en) * 1994-01-28 1997-08-12 Lucent Technologies Inc. Voice activity detection driven noise remediator
US5911128A (en) * 1994-08-05 1999-06-08 Dejaco; Andrew P. Method and apparatus for performing speech frame encoding mode selection in a variable rate encoding system
US6484138B2 (en) 1994-08-05 2002-11-19 Qualcomm, Incorporated Method and apparatus for performing speech frame encoding mode selection in a variable rate encoding system
US5742734A (en) * 1994-08-10 1998-04-21 Qualcomm Incorporated Encoding rate selection in a variable rate vocoder
WO1996013916A1 (fr) * 1994-10-28 1996-05-09 International Mobile Satellite Organization Procede de communication et dispositif de transmission d'un second signal en l'absence d'un premier
DE19630113C2 (de) * 1995-08-02 2003-09-18 Motorola Inc Verfahren zum Senden von Daten während Sprachpausen in einem synchronen Kommunikationssystem
US5625687A (en) * 1995-08-31 1997-04-29 Lucent Technologies Inc. Arrangement for enhancing the processing of speech signals in digital speech interpolation equipment
US5615214A (en) * 1995-10-30 1997-03-25 Motorola, Inc. System and method of compensating propagation time variations and substituting for lost packets in a packetized voice communication system
US5751901A (en) * 1996-07-31 1998-05-12 Qualcomm Incorporated Method for searching an excitation codebook in a code excited linear prediction (CELP) coder
US5881373A (en) * 1996-08-28 1999-03-09 Telefonaktiebolaget Lm Ericsson Muting a microphone in radiocommunication systems
US6295302B1 (en) 1998-04-24 2001-09-25 Telefonaktiebolaget L M Ericsson (Publ) Alternating speech and data transmission in digital communications systems
US6438131B1 (en) * 1998-07-28 2002-08-20 Lucent Technologies Inc. Low-overhead service specific convergence layer for voice and telephony over packet-based systems
US7496505B2 (en) 1998-12-21 2009-02-24 Qualcomm Incorporated Variable rate speech coding
US6691084B2 (en) 1998-12-21 2004-02-10 Qualcomm Incorporated Multiple mode variable rate speech coding
US7065498B1 (en) * 1999-04-09 2006-06-20 Texas Instruments Incorporated Supply of digital audio and video products
US7835311B2 (en) * 1999-12-09 2010-11-16 Broadcom Corporation Voice-activity detection based on far-end and near-end statistics
US20080049647A1 (en) * 1999-12-09 2008-02-28 Broadcom Corporation Voice-activity detection based on far-end and near-end statistics
US20110058496A1 (en) * 1999-12-09 2011-03-10 Leblanc Wilfrid Voice-activity detection based on far-end and near-end statistics
US8565127B2 (en) * 1999-12-09 2013-10-22 Broadcom Corporation Voice-activity detection based on far-end and near-end statistics
US6873604B1 (en) * 2000-07-31 2005-03-29 Cisco Technology, Inc. Method and apparatus for transitioning comfort noise in an IP-based telephony system
US20060227963A1 (en) * 2005-04-07 2006-10-12 Ascalade Communications Inc. Wireless multi-unit conference phone
US8457614B2 (en) 2005-04-07 2013-06-04 Clearone Communications, Inc. Wireless multi-unit conference phone
US20070248813A1 (en) * 2006-04-25 2007-10-25 Xerox Corporation Imaging member having styrene
RU2651803C1 (ru) * 2016-12-22 2018-04-24 Акционерное общество "Научно-производственное предприятие "Полет" Подавитель шума

Also Published As

Publication number Publication date
CA1332453C (fr) 1994-10-11
JPH0239744A (ja) 1990-02-08
EP0348078A2 (fr) 1989-12-27
AU3596989A (en) 1989-12-21
AU596333B2 (en) 1990-04-26
EP0348078A3 (fr) 1992-03-11
CN1038730A (zh) 1990-01-10
KR920007478B1 (ko) 1992-09-04
KR910002146A (ko) 1991-01-31

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